Methods and compositions for treating post-myocardial infarction damage

ABSTRACT

Methods and compositions for treating post-myocardial infarction damage are herein disclosed. In some embodiments, a carrier with a treatment agent may be fabricated. The carrier can be formulated from a bioerodable, sustained-release substance. The resultant loaded carrier may then be suspended in at least one component of a two-component matrix system for simultaneous delivery to a post-myocardial infarction treatment area.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a divisional of U.S. patent application Ser. No. 11/447,340,filed Jun. 5, 2006, which is a continuation-in-part of U.S. patentapplication Ser. No. 11/361,920, filed Feb. 23, 2006, which is acontinuation-in-part of U.S. patent application Ser. No. 11/110,223,filed Apr. 19, 2005, and incorporated herein by reference.

FIELD OF INVENTION

Post-myocardial infarction treatments and compositions.

BACKGROUND OF INVENTION

Ischemic heart disease typically results from an imbalance between themyocardial blood flow and the metabolic demand of the myocardium.Progressive atherosclerosis with increasing occlusion of coronaryarteries leads to a reduction in coronary blood flow. “Atherosclerosis”is a type of arteriosclerosis in which cells including smooth musclecells and macrophages, fatty substances, cholesterol, cellular wasteproduct, calcium and fibrin build up in the inner lining of a bodyvessel. “Arteriosclerosis” refers to the thickening and hardening ofarteries. Blood flow can be further decreased by additional events suchas changes in circulation that lead to hypoperfusion, vasospasm orthrombosis.

Myocardial infarction (MI) is one form of heart disease that oftenresults from the sudden lack of supply of oxygen and other nutrients.The lack of blood supply is a result of a closure of the coronary artery(or any other artery feeding the heart) which nourishes a particularpart of the heart muscle. The cause of this event is generallyattributed to arteriosclerosis in coronary vessels.

Formerly, it was believed that an MI was caused from a slow progressionof closure from, for example, 95% then to 100%. However, an MI can alsobe a result of minor blockages where, for example, there is a rupture ofthe cholesterol plaque resulting in blood clotting within the artery.Thus, the flow of blood is blocked and downstream cellular damageoccurs. This damage can cause irregular rhythms that can be fatal, eventhough the remaining muscle is strong enough to pump a sufficient amountof blood. As a result of this insult to the heart tissue, scar tissuetends to naturally form.

Various procedures, including mechanical and therapeutic agentapplication procedures, are known for reopening blocked arties. Anexample of a mechanical procedure includes balloon angioplasty withstenting, while an example of a therapeutic agent application includesthe administration of a thrombolytic agent, such as urokinase. Suchprocedures do not, however, treat actual tissue damage to the heart.Other systemic drugs, such as ACE-inhibitors and Beta-blockers, may beeffective in reducing cardiac load post-MI, although a significantportion of the population that experiences a major MI ultimately developheart failure.

An important component in the progression to heart failure is remodelingof the heart due to mismatched mechanical forces between the infractedregion and the healthy tissue resulting in uneven stress and straindistribution in the left ventricle. Once an MI occurs, remodeling of theheart begins. The principle components of the remodeling event includemyocyte death, edema and inflammation, followed by fibroblastinfiltration and collagen deposition, and finally scar formation. Theprinciple component of the scar is collagen. Since mature myocytes of anadult are not regenerated, the infarct region experiences significantthinning. Myocyte loss is the major etiologic factor of wall thinningand chamber dilation that may ultimately lead to progression of cardiacmyopathy. In other areas, remote regions experience hypertrophy(thickening) resulting in an overall enlargement of the left ventricle.This is the end result of the remodeling cascade. These changes in theheart result in changes in the patient's lifestyle and their ability towalk and to exercise. These changes also correlate with physiologicalchanges that result in increase in blood pressure and worsening systolicand diastolic performance.

SUMMARY OF INVENTION

Methods and compositions for treating post-myocardial infarction damageare herein disclosed. In some embodiments, a carrier may be loaded witha treatment agent. The carrier can be formulated from a bioerodable,sustained-release substance. The resultant loaded carrier may then besuspended in one component of a two-component matrix for simultaneousdelivery to a post-myocardial infarction treatment area.

BRIEF DESCRIPTION OF DRAWINGS

FIGS. 1A-1B illustrate the progression of heart damage once the build-upof plaque in an artery induces an infarct to occur.

FIG. 2 schematically represents a method for preparing a two-componentgel matrix with a sustained carrier loaded with treatment agentinterdispersed therein.

FIG. 3 schematically represents an alternative method for preparing atwo-component gel matrix with a sustained carrier loaded with treatmentagent interdispersed therein.

FIG. 4 schematically represents a second alternative method forpreparing a two-component gel matrix with a sustained carrier loadedwith treatment agent interdispersed therein.

FIGS. 5A-5B illustrate an embodiment of a dual-needle injection devicewhich can be used to deliver the compositions of the present invention.

FIGS. 6A-6C illustrate an alternative embodiment of a dual-needleinjection device which can be used to deliver the compositions of thepresent invention

DETAILED DESCRIPTION

Methods and compositions for treating post-myocardial infarction damageare herein disclosed. In some embodiments, a carrier with a treatmentagent may be fabricated. The carrier can be formulated from abioerodable, sustained-release substance. The resultant loaded carriermay then be suspended in at least one component of a two-componentmatrix system for simultaneous delivery to a post-myocardial infarctiontreatment area.

FIGS. 1A-1B illustrate the progression of heart damage once the build-upof plaque induces an infarct to occur. FIG. 1A illustrates a site 10where blockage and restricted blood flow can occur from, for example, athrombus or embolus. FIG. 1B illustrates resultant damage area 20 to theleft ventricle that can result from the lack of oxygen and nutrient flowcarried by the blood to the inferior region left of the heart. Thedamage area 20 will likely undergo remodeling, and eventually scarring,resulting in a non-functional area.

Treatment Agents

Treatment agents to treat post-myocardial infarction treatment areas mayinclude: (i) agents that promote angiogenesis (angiogenesis promotingfactors); (ii) agents that promote cell survival (cell survivalpromoting factors); and (iii) agents that recruit endogenous progenitorand/or stem cells (endogenous recruiting factors). Various forms oftreatment agents are intended to include, but are not intended to belimited to, drugs, biologically active agents, chemically active agents,therapeutic agents, and the like, and pharmaceutical compositionsthereof, which can be used in the delivery of a treatment agent to atreatment site as described herein.

“Angiogenesis” is the promotion or causation of the formation of newblood vessels. After an MI, the infarct tissue as well as the borderzone and the remote zone around the infarct tissue begin to remodel.Scar tissue forms in the infarct region as the granulation is replacedwith collagen. Stress from blood pressure cause the scar to thin out andstretch. The perfusion in this region is typically 10% of the healthyzone, decreasing the number of active capillaries. Increasing the numberof capillaries may lead to an increase in compliance of the ventricledue to filling up with blood. Other benefits of increasing blood flow tothe infarcted region include providing a route for circulating stemcells to seed and proliferate in the infarct region. Angiogenesis mayalso lead to increased oxygenation for the surviving cellular isletswithin the infarct region, or to prime the infarct region for subsequentcell transplantation for myocardial regeneration. In the border zone,surviving cells would also benefit from an increase in blood supplythrough an angiogenesis process. In the remote zone, where cardiac cellstend to hypertrophy and become surrounded with some interstitialfibrosis, the ability of cells to receive oxygen and therefore functionto full capacity are also compromised; thus, angiogenesis would bebeneficial in these regions as well.

In some embodiments, angiogenesis promoting factors include, but are notintended to be limited to, growth factors such as isoforms ofvasoendothelial growth factor (VEGF), fibroblast growth factor (FGF,e.g. beta-FGF), Del 1, hypoxia inducing factor (HIF 1-alpha), monocytechemoattractant protein (MCP-1), nicotine, platelet derived growthfactor (PDGF), insulin-like growth factor 1 (IGF-1), transforming growthfactor (TGF alpha), hepatocyte growth factor (HGF), estrogens,follistatin, proliferin, prostaglandin E1 and E2, tumor necrosis factor(TNF-alpha), interleukin 8 (Il-8), hematopoietic growth factors,erythropoietin, granulocyte-colony stimulating factors (G-CSF) andplatelet-derived endothelial growth factor (PD-ECGF). In someembodiments, angiogenesis promoting factors include, but are notintended to be limited to, peptides, such as PR39, PR11 and angiogenin,small molecules, such as PHD inhibitors, or other agents, such as eNOSenhancers.

Endogenous cardiomyocyte (myocytes) apoptosis is the major etiologicalfactor of wall thinning and chamber dilation and may ultimately lead toprogression of cardiac myopathy. After an infarction, mature myocytes ofan adult are not regenerated which can lead to significant thinning inthe infarct region. Thus, factors which promote cell survival applied tothe infarct region are believed to be beneficial. In some embodiments,cell survival promoting factors include, but are not intended to belimited to, growth factors such as insulin-like growth factor (IGF-1)and human growth factor (HGF), which are known to mediate cell growth,differentiation and survival of a variety of cell types. In addition,small molecules such as, for example, HMG-CoA reductase inhibitors(statins) and capsase inhibitors can also promote cell survival andinhibit apoptosis.

To assist in the generation of new cells at the infarct region,autologous or allogeneic stem cells may be delivered to a patient.“Autologous” means the donor and recipient of the stem cells are thesame. “Allogeneic” means the donor and recipient of the stem cells aredifferent. Cell survival promoting factors can also be used to increasethe survivability of autologous and allogeneic implanted stem cells atthe infarct region.

Cardiac progenitor cells are highly specialized stem cells which haveshown the ability to differentiate into certain types of fully maturecardiac tissue. Examples of cardiac progenitor cells include, but arenot limited to, c-Kit(+), Sca-1(+) and Isl-1(+). Thus, factors whichrecruit endogenous factors when applied to the infarct region arebelieved to be beneficial. In some embodiments, an endogenous recruitingfactor can include, for example, HGF. HGF has been shown to control cellmotility and promote cell migration. If applied post-infarction, HGF canassist in mobilizing and recruiting resident cardiac progenitor cells tothe infarct region. In some embodiments, an endogenous recruiting factorcan include, but is not intended to be limited to, stromal cell-derivedfactor 1 (SDF-1). SDF-1 is the ligand for the CXCR4 receptor, which is asurface receptor on circulating endothelial progenitor cells. Thus, whenapplied in or around the infarct region, SDF-1 may facilitate the homingof circulating endothelial progenitor cells to induceneovascularization.

It is contemplated that any of the above-described treatment agents canbe used singularly or in combination thereof. In addition, othertreatment agents, including but not limited to, anti-inflammatory,anti-platelet, anti-coagulant, anti-fibrin, anti-thrombotic,anti-mitotic, anti-biotic, anti-allergic, anti-oxidant,anti-proliferative, or anti-migratory agents, may be optionally usedsingularly or in combination thereof.

Sustained-Release Carriers

Bioerodable carriers (hereinafter interchangeably referred to assustained-release carriers) infused with (or without) a treatment agentcan be used for the sustained or controlled release of treatment agentfor maximum benefit to the infarct region. It is believed that a largepercentage of treatment agent delivered directly to the infarct region,or even diffused within a gel-like matrix, will be substantially washedaway by the body's natural mechanisms, thus lessening the benefit of thetreatment agent that may otherwise be obtained. Thus, sustained-releasecarriers infused with treatment agent that release the treatment agentover an extended time period can be beneficial by increasing the amountof time in which the infarct region is exposed to the treatment agent.Sustained-release carriers include, but are not limited to, (i)microparticles or nanoparticles (hereinafter interchangeably referred toas microparticles), (ii) microfibers or nanofibers (hereinafterinterchangeably referred to as microfibers) and (iii) liposomes andpolymerosomes.

In addition, in some embodiments, a bioerodable carrier may be infusedwith (or without) a treatment agent and delivered to a treatment site toact as a “docking site” for endogenous myocardial stem cells andencourage their differentiation into cardiomyocytes.

A.

In some embodiments, the sustained-release carrier is a microparticle.Various methods can be employed to formulate and infuse or load themicroparticles with treatment agent. In some embodiments, themicroparticles are prepared by a water/oil/water (W/O/W) double emulsionmethod. In the W1 phase, an aqueous phase containing treatment agent, isdispersed into the oil phase consisting of polymer dissolved in organicsolvent (e.g., dichloromethane) using a high-speed homogenizer. Examplesof sustained-release polymers include, but are not limited to,poly(D,L-lactide-co-glycolide) (PLGA), poly(D,L-lactide) (PLA) orPLA-PEEP co-polymers, poly-ester-amide co-polymers (PEA) andpolyphophazines. The primary water-in-oil (W/O) emulsion is thendispersed to an aqueous solution containing a polymeric surfactant,e.g., poly(vinyl alcohol) (PVA), and further homogenized to produce aW/O/W emulsion. After stirring for several hours, the microparticles arecollected by filtration.

B.

In some embodiments, the sustained-release carrier is a microfiber ornanofiber. For example, the treatment agent (or no treatment agent)infused microfiber can be formulated by electrospinning“Electrospinning” is a process by which microfibers are formed by usingan electric field to draw a polymer solution from the tip of a capillaryto a collector. A voltage is applied to the polymer solution whichcauses a stream of solution to be drawn toward a grounded collector.Electrospinning generates a web of fibers which can be subsequentlyprocessed into smaller lengths.

Examples of sustained-release polymers which can be used inelectrospinning include, but are not limited to, PLGA, PLA or PLA-PEEPco-polymers, PEA, polyphosphazines and collagen. In one method, thetreatment agent is mixed with a bioerodable polymer solution, a solventand a surfactant. Examples of surfactants can include, but are notlimited to, anionic or cationic surfactants. Useful anionic surfactantsinclude, but are not intended to be limited to, bis(2-ethylhexyl) sodiumsulfosuccinate (AOT), bis(2-ethylhexyl) phosphate (NaDEHP),tauroglycocholate, and sodium lauryl sulfate. A useful cationicsurfactant is tetradecyltrimethyl-ammonium bromide (TTAB). An example ofa solvent includes, but is not limited to, hexafluoro isopropanol. Thetreatment agent-infused polymer solution is then subjected toelectrospinning. As the solvent evaporates during electrospinning, thetreatment agent incorporates and distributes within the polymer bynon-covalent interactions. The resultant microfibers which can be fromabout 0.5 μm to about 3 μm in diameter form a web which may then beprocessed into smaller lengths of about 0.5 μm to about 500 μm. Based onthe treatment agent, in some applications, microfibers may be apreferred sustained-release carrier due to the non-aqueous process bywhich they are formed. In some applications, microspheres may bepreferable when the treatment agent is hydrophilic. In someapplications, a microfiber is a preferred sustained-release carrier dueto its release pharmacokinetic profile when compared to the releasepharmacokinetic profile of a microsphere. In some cases, microspheres aswell as microfibers can be used as a carrier of one or more than onetreatment agent as the two types of carriers will provide differentpharmacokinetic release profiles which may be advantageous for therapy.

In one embodiment, fibers can be electrospun from collagen and elastindissolved in 1,1,1,3,3,3-hexafluoro-2-propanol (HFP), forming a polymersolution. A treatment agent can be added to the polymer solution. Asurfactant and a stabilizer can be used to evenly disperse the treatmentagent in the solvent. The polymer solution can then be loaded into asyringe and placed in a syringe pump for metered dispensing at apredetermined rate. A positive output lead of a high voltage supply canbe attached to a needle on the syringe. The needle can be directed to astainless steel grounded target placed approximately 10 cm from theneedle tip, which can be rotated at a predetermined speed to ensure aneven coating. The distance of the needle from the target can be varieddepending upon the diameter of the fibers needed. The resultantmicrofibers are from about 0.5 μm to about 3 μm in diameter and theresulting non-woven mat of fibers can then be processed into smallerlengths of about 0.5 μm to about 500 μm.

C.

In some embodiments, the sustained-release carrier is a liposome or apolymerosome. “Liposomes” are artificial vesicles that are approximatelyspherical in shape and can be produced from natural phospholipids andcholesterol. In one method, phospholipids are mixed with cholesterol inchloroform. Suitable phospholipids include, but are not limited to,dimyristoyl phosphatidyl choline or dipalmitoyl ethanolamine. In someembodiments, hydrophobic treatment agent can be added with an optionalco-solvent, such as heptane or toluene. The liposomes may also behydrophilically modified with an agent such as polyethylene glycol ordextran. After mixing, the solvent (and optional co-solvent) can beevaporated with heat or ambient temperature in a round bottom flask.Resultant lipids will be deposited on the glass surface. In someembodiments, hydrophilic treatment agent and water can be added to theflask and sonicated to form liposomes. The resultant suspension can bepressure filtered through ceramic pore size controlled filters to reduceliposome particle size. In the case of a polymerosome, a similarmanufacturing technique can be used as that of a liposome. Polymerosomescan be formed from di-block co-polymers of differing solubility. Forexample, one block can be hydrophobic, e.g., poly lactic acid,polycaprolactone, n-butyl acrylate, and the other block can behydrophilic, e.g., poly(ethylene glycol), poly(acrylic acid).

Matrix Systems

A biocompatible matrix system can be used to suspend the treatment agentor the treatment agent-infused sustained-release carrier for delivery tothe infarct region. In some embodiments, the matrix system can be aone-component or a two-component gel. In some embodiments, the matrixsystem is a two-component gel. Two-component gels can include, forexample, fibrin glues (e.g., two components comprising fibrinogen andthrombin), self-assembled peptides or alginate constructs.

In some embodiments, the matrix system is a one-component gel. Anexample of a one-component gel includes an acrylate agent that isbiocompatible. The one-component gel serves in one aspect to dispersethe sustained-release carrier in order to form a more uniform scaffoldover the entire infarct zone and may include border zone as well. Forexample, the one-component gel may be sodium hyaluronate. The geldisperses the sustained-release carrier acting as a suspending media.

A.

In some applications, the two-component gelation system includes afibrin glue. Fibrin glue consists of two main components, fibrinogen andthrombin. Fibrinogen is a plasma glycoprotein of about 340 kiloDaltons(kDa) in its endogenous state. Fibrinogen is a symmetrical dimercomprised of six paired polypeptide chains, alpha, beta and gammachains. On the alpha and beta chains, there is a small peptide sequencecalled a fibrinopeptide which prevent fibrinogen from spontaneouslyforming polymers with itself. In some embodiments, fibrinogen ismodified with proteins. Thrombin is a coagulation protein. When combinedin equal volumes, thrombin converts the fibrinogen to fibrin byenzymatic action at a rate determined by the concentration of thrombin.The result is a biocompatible gel which gelates when combined at theinfarct region. Fibrin glue can undergo gelation at about 10 to about 60seconds. Examples of other fibrin glue-like systems include, but are notlimited to, Tisseel™ (Baxter), CoSeal™ (Baxter), Crosseal™ (OmrixBiopharmaceuticals, Ltd.), Hemaseel® (Haemacure Corp.) and CoStasis®(Angiotech Pharmaceuticals).

B.

In some embodiments, the two-component gel comprises self-assembledpeptides. Self-assembled peptides generally include repeat sequences ofalternating hydrophobic and hydrophilic amino acid chains. Thehydrophilic amino acids are generally charge-bearing and can be anionic,cationic or both. Examples of cationic amino acids are lysine andarginine. Examples of anionic amino acids are aspartic acid and glutamicacid. Examples of hydrophobic amino acids are alanine, valine, leucine,isoleucine or phenylalanine. Self-assembled peptides can range from 8 toabout 40 amino acids in length and can assemble into nanoscale fibersunder conditions of physiological pH and osmolarity. In sufficientconcentration and over time, the fibers can assemble into aninterconnected structure that appears macroscopically as a gel.Self-assembled peptides typically undergo gelation between severalminutes to several hours. Examples of self-assembled peptides include,but are not limited to: AcN-RARADADARARADADA -CNH₂ (RAD 16-II) [SEQ IDNO: 1] wherein R is arginine, A is alanine, D is aspartic acid, and Acindicates acetylation; VKVKVKVKV-PP-TKVKVKVKV-NH ₂ (MAX-1) [SEQ ID NO:2] wherein V is valine, K is lysine and P is proline; andAcN-AEAEAKAKAEAEAKAK -CNH₂ (EAK16-II) [SEQ ID NO: 3] wherein A isalanine, K is lysine and E is glutamic acid.

Example

In one example, the self-assembled peptide is RAD 16-II. At low pH andosmolarity, RAD 16-II forms a solution. At physiological pH andosmolarity, RAD 16-II forms a gel although gel formation can be slow. Insome embodiments, RAD 16-II is mixed with phosphate buffer saline (PBS)to form a first component solution. In some embodiments, the firstcomponent solution can be co-injected with a second component comprisingsodium chloride, sucrose or other osmolarity modifying substance using,for example, a dual-injection delivery assembly. In some embodiments,the components can be co-injected with carriers such as angiogenesispromoting factors, cell survival promoting factors and/or endogenousrecruiting factors. These factors bind non-specifically to theself-assembled peptides by electrostatic interactions, and this bindingcan control or retard the release of the factors.

C.

In some embodiments, the two-component gel is an alginate construct. Forexample, the alginate construct may be collagen or gelatin graftedalginate. In one example, a first component can be a solution of about0.5 percent to about 1.0 percent alginate while a second component canbe a solution of about 40 mM to about 180 mM calcium chloride. Oneexample of a suitable amount of components is about 200 microliters ofalginate solution and about 200 microliters of calcium chloride. In oneembodiment, a desired amount of a treatment agent may be introduced withthe alginate solution.

Methods of Manufacture

FIG. 2 schematically represents a method for preparing a two-componentgel matrix with a sustained carrier loaded with treatment agentinterdispersed therein. A treatment agent, such as an angiogenesispromoting factor, cell survival promoting factor, endogenous recruitingfactor or any combination thereof can be added to a bioerodable polymersuch as PLGA or PEA and PLA-PEEP co-polymers or polyphosphazenes (100).In some embodiments, a W/O/W process can be used. The mixture can beprocessed to monodisperse the resultant treatment agent loadedmicrospheres (110). The microspheres can be in a range from about 5 μmto about 200 μm, preferably from about 10 μm to about 50 μm. Next, theresultant dispersion can be added to one component of a two-componentgel such as fibrin glue (120). In one embodiment, the two-component gelincludes component A and component B, wherein component A is fibrinogenand component B is thrombin. Component A and component B can then beseparately but simultaneously injected into the myocardial infarctregion by a dual-injection delivery assembly for treatment thereof(130).

FIG. 3 schematically represents an alternative method for preparing atwo-component gel matrix with a sustained carrier loaded with treatmentagent interdispersed therein. A treatment agent, such as an angiogenesispromoting factor, cell survival promoting factor, endogenous recruitingfactor or any combination thereof can be added to a bioerodable polymersuch as PLGA or PEA and PLA-PEEP co-polymers or polyphosphazenes orcollagen (200) with solvent. For collagen/elastin electrospun fibers, asuitable solvent can be HFP. In some embodiments, an aqueous system maybe used. The mixture can then be subjected to electrospinning to createinterwoven fibers (210) with a diameter in a range from about 0.2 μm toabout 3 μm. The fibers may then be processed into smaller of length fromabout 0.5 μm to about 500 μm (220). The fibers may be processed bycryogenic grinding, subjected to ultrasound in water, or subjected toultrasound in a volatile solvent that is a non-solvent for both thepolymer and the encapsulated protein or other agent or subjected to anyother suitable method to reduce their size. Next, the resultant fiberscan be added to one component of a two-component gel such as fibrin glue(230). In one embodiment, the two-component gel includes component A andcomponent B, wherein component A is fibrinogen and component B isthrombin. Component A and component B can then be separately butsimultaneously injected into the myocardial infarct region by adual-injection delivery assembly for treatment thereof (240).

FIG. 4 schematically represents another alternative method for preparinga two-component gel matrix with a sustained carrier loaded withtreatment agent interdispersed therein. A phospholipid substance can becombined with cholesterol in a solvent such as chloroform (300) in around bottom flask. In some embodiments, a hydrophobic treatment agentincluding an optional co-solvent can be added thereto (300A). Thesolvent(s) can be evaporated depositing lipids on the glass surface(310). Next, water is added and in some embodiments, a hydrophilictreatment agent (320). Then, the mixture is sonicated to form liposomes(330) and optionally pressure-filtered to reduce liposome particle size(340). Next, the resultant liposomes can be added to one component of atwo-component gel such as fibrin glue (350). In one embodiment, thetwo-component gel includes component A and component B, whereincomponent A is fibrinogen and component B is thrombin. Component A andcomponent B can then be separately but simultaneously injected into themyocardial infarct region by a dual-injection delivery assembly fortreatment thereof (360).

Example

In one embodiment, collagen electrospun fibers can be processed to arange from about 200 nm and about 1300 nm. The range of electrospunfibers is approximately the range of naturally occurring type 1 and type3 fibers which make up the heart matrix. Thus, the electrospun fibersmay mimic endogenous fibers and accelerate growth of repair tissue tothe infarct region, in particular, on the heart. The fibers can bedispersed throughout one component of a two-component gel. The twocomponents can then be delivered to myocardial infarct region. Thefibers can provide “docking sites” for endogenous myocardial stem cellsand encourage their differentiation into cardiomyocytes. The gel canprovide temporary containment of the fibers and prevent prematureremoval by macrophage cells.

The fibers can be fabricated such that they include an agent or noagent. Examples of agents can include a chemoattractant, such as SDF-1,or a cell survival promoting factor, such as IGF-1. In one embodiment,SDF-1 may be incorporated within the electrospun fibers and theresultant agent infused electrospun fibers may be dispersed throughoutone component of a two-component gel. When delivered, the release ofSDF-1 may recruit endogenous stem cells to the infarct region where theywill adhere to the electrospun fibers and differentiate into stem cells.

In another embodiment, IGF-1 may be incorporated within the electrospunfibers and the resultant agent infused electrospun fibers may bedispersed throughout one component of a two-component gel. Stem cellsmay be incorporated within the other component of the two-component gel.When delivered, the stem cells may be temporally immobilized in the geland adhere to the electrospun fibers. IGF-1 may enhance stem cellsurvival.

It should be appreciated that any of the above-described methods may becombined to treat an infarct region.

Methods of Treatment

Devices which can be used to deliver each component of the gel include,but are not limited to, dual-needle left-ventricle injection devices anddual-needle transvascular wall injection. Methods of access to use theinjection devices include access via the femoral artery or thesub-xiphoid. “Xiphoid” or “xiphoid process” is a pointed cartilageattached to the lower end of the breastbone or sternum, the smallest andlowest division of the sternum. Both methods are known by those skilledin the art.

FIGS. 5A-5B illustrate an embodiment of a dual-needle injection devicewhich can be used to deliver the compositions of the present invention.Delivery assembly 400 includes lumen 410 which may house deliverylumens, guidewire lumens and/or other lumens. Lumen 410, in thisexample, extends between distal portion 405 and proximal end 415 ofdelivery assembly 400.

In one embodiment, delivery assembly 400 includes main needle 420disposed within delivery lumen 430. Main needle 420 is movably disposedwithin delivery lumen 430. Main needle 420 is, for example, a stainlesssteel hypotube that extends a length of the delivery assembly. Mainneedle 420 includes a lumen with an inside diameter of, for example,0.08 inches (0.20 centimeters). In one example for a retractable needlecatheter, main needle 420 has a needle length on the order of 40 inches(1.6 meters) from distal portion 405 to proximal portion 415. Lumen 410also includes separate, possibly smaller diameter, auxiliary lumen 440extending, in this example, co-linearly along the length of the catheter(from a distal portion 405 to proximal portion 415). Auxiliary lumen 440is, for example, a polymer tubing of a suitable material (e.g.,polyamides, polyolefins, polyurethanes, etc.). At distal portion 405,auxiliary lumen 440 is terminated to auxiliary needle end 450co-linearly aligned with a delivery end of needle 420. Auxiliary lumen440 may be terminated to auxiliary needle end 450 with aradiation-curable adhesive, such as an ultraviolet curable adhesive.Auxiliary needle end 450 is, for example, a stainless steel hypotubethat is joined co-linearly to the end of main needle 420 by, forexample, solder (illustrated as joint 455). Auxiliary needle end 450 hasa length on the order of about 0.08 inches (0.20 centimeters). FIG. 5Bshows a cross-sectional front view through line A-A′ of deliveryassembly 400. FIG. 5B shows main needle 420 and auxiliary needle 450 ina co-linear alignment.

Referring to FIG. 5A, at proximal portion 415, auxiliary lumen 440 isterminated to auxiliary side arm 460. Auxiliary side arm 460 includes aportion extending co-linearly with main needle 420. Auxiliary side arm460 is, for example, a stainless steel hypotube material that may besoldered to main needle 420 (illustrated as joint 465). Auxiliary sidearm 460 has a co-linear length on the order of about, in one example,1.2 inches (3 centimeters).

The proximal end of main needle 420 includes adaptor 470 foraccommodating a substance delivery device (e.g., a component of atwo-component bioerodable gel material). Adaptor 470 is, for example, amolded female luer housing. Similarly, a proximal end of auxiliary sidearm 460 includes adaptor 480 to accommodate a substance delivery device(e.g., a female luer housing).

The design configuration described above with respect to FIGS. 5A-5B issuitable for introducing two-component gel compositions of the presentinvention. For example, a gel may be formed by a combination (mixing,contact, etc.) of a first component and a second component.Representatively, a first component may be introduced by a one cubiccentimeters syringe at adaptor 470 through main needle 420. At the sametime or shortly before or after, second component including treatmentagent loaded sustained-release particles may be introduced with a onecubic centimeter syringe at adaptor 480. When the first and secondcomponents combine at the exit of delivery assembly 400 (at an infarctregion), the materials combine (mix, contact) to form a bioerodable gel.

FIGS. 6A-6C illustrate an alternative embodiment of a dual-needleinjection device which can be used to deliver two-component gelcompositions of the present invention. In general, the catheter assembly500 provides a system for delivering substances, such as two-componentgel compositions, to or through a desired area of a blood vessel (aphysiological lumen) or tissue in order to treat a myocardial infarctregion. The catheter assembly 500 is similar to the catheter assembly500 described in commonly-owned, U.S. Pat. No. 6,554,801, titled“Directional Needle Injection Drug Delivery Device”, and incorporatedherein by reference.

In one embodiment, catheter assembly 500 is defined by elongatedcatheter body 550 having proximal portion 520 and distal portion 510.FIG. 6B shows catheter assembly 500 through line A-A′ of FIG. 6A (atdistal portion 510). FIG. 6C shows catheter assembly 500 through lineB-B′ of FIG. 6A.

Guidewire cannula 570 is formed within catheter body (from proximalportion 510 to distal portion 520) for allowing catheter assembly 500 tobe fed and maneuvered over guidewire 580. Balloon 530 is incorporated atdistal portion 510 of catheter assembly 500 and is in fluidcommunication with inflation cannula 560 of catheter assembly 500.

Balloon 530 can be formed from balloon wall or membrane 335 which isselectively inflatable to dilate from a collapsed configuration to adesired and controlled expanded configuration. Balloon 530 can beselectively dilated (inflated) by supplying a fluid into inflationcannula 560 at a predetermined rate of pressure through inflation port565. Balloon wall 335 is selectively deflatable, after inflation, toreturn to the collapsed configuration or a deflated profile. Balloon 530may be dilated (inflated) by the introduction of a liquid into inflationcannula 560. Liquids containing treatment and/or diagnostic agents mayalso be used to inflate balloon 530. In one embodiment, balloon 530 maybe made of a material that is permeable to such treatment and/ordiagnostic liquids. To inflate balloon 530, the fluid can be suppliedinto inflation cannula 560 at a predetermined pressure, for example,between about one and 20 atmospheres. The specific pressure depends onvarious factors, such as the thickness of balloon wall 335, the materialfrom which balloon wall 335 is made, the type of substance employed andthe flow-rate that is desired.

Catheter assembly 500 also includes substance delivery assembly 505 forinjecting a substance into a myocardial infarct region. In oneembodiment, substance delivery assembly 505 includes needle 515 amovably disposed within hollow delivery lumen 525 a. Delivery assembly505 includes needle 515 b movably disposed within hollow delivery lumen525 b. Delivery lumen 525 a and delivery lumen 525 b each extend betweendistal portion 510 and proximal portion 520. Delivery lumen 525 a anddelivery lumen 525 b can be made from any suitable material, such aspolymers and copolymers of polyamides, polyolefins, polyurethanes andthe like. Access to the proximal end of delivery lumen 525 a or deliverylumen 525 b for insertion of needle 515 a or 515 b, respectively isprovided through hub 535. Delivery lumens 525 a and 525 b may be used todeliver first and second components of a two-component gel compositionto a myocardial infarct region.

From the foregoing detailed description, it will be evident that thereare a number of changes, adaptations and modifications of the presentinvention which come within the province of those skilled in the part.The scope of the invention includes any combination of the elements fromthe different species and embodiments disclosed herein, as well assubassemblies, assemblies and methods thereof. However, it is intendedthat all such variations not departing from the spirit of the inventionbe considered as within the scope thereof.

What is claimed is:
 1. A method of manufacturing a compositioncomprising: combining at least one treatment agent selected for treatinga post-myocardial infarction area of a heart with a precursor of asustained-release carrier in a solvent to form a mixture; processing themixture to form a sustained-release carrier loaded with the at least onetreatment agent; adding the sustained-release carrier loaded with the atleast one treatment agent to a first component solution of atwo-component gel system; and combining the first component solutionhaving the sustained-release carrier loaded with the at least onetreatment agent therein and a second component solution of thetwo-component gel system in situ to form a gel scaffold to support atissue within the post-myocardial infarction area of the heart byseparately injecting the first component solution and the secondcomponent solution into the post-myocardial infarction area of theheart, and wherein the two-component gel system is selected from thegroup consisting of an alginate construct system, a fibrin glue systemand a self-assembled peptide system.
 2. The method of claim 1, whereinthe processing comprises subjecting the mixture to electrospinning toform fibers loaded with treatment agent.
 3. The method of claim 2,wherein combining comprises combining a solvent with the treatmentagent, the solvent is non-aqueous.
 4. The method of claim 2, whereinprior to processing a surfactant is added to the mixture.
 5. The methodof claim 1, wherein the two-component gel system is an alginateconstruct system comprising collagen grafted alginate as the firstcomponent and calcium chloride as the second component.
 6. The method ofclaim 1, wherein the two-component gel system is a self-assembledpeptide system comprising one of RAD 16-II, MAX-1 or EAK16-II as thefirst component and one of sucrose or sodium chloride as the optionalsecond component.
 7. The method of claim 1, wherein the gel thetwo-component gel system is a fibrin glue system comprising fibrinogenor a derivative thereof as the first component and thrombin as thesecond component.
 8. The method of claim 1, wherein the carrier isselected from the group consisting of bioerodable polymers andliposomes.
 9. The method of claim 1, wherein the carrier is a particle.10. The method of claim 9, wherein the particle is one of a microsphere,a nanosphere or a polymerosome.
 11. The method of claim 10, wherein theparticle is one of an electrospun microfiber or a nanofiber.
 12. Themethod of claim 1, wherein the treatment agent is selected from thegroup consisting of an angiogenesis promoting factor, a cell survivalpromoting factor and an endogenous recruiting factor.
 13. The method ofclaim 12, wherein the angiogenesis promoting factor is selected from thegroup consisting of vasoendothelial growth factor, fibroblast growthfactor, Del 1, hypoxia inducing factor, monocyte chemoattractantprotein, nicotine, platelet derived growth factor, insulin-like growthfactor 1, transforming growth factor, hepatocyte growth factor,estrogens, follistatin, proliferin, prostaglandin E1, prostaglandin E2,tumor necrosis factor, Interleukin 8, hematopoietic growth factors,erythropoietin, granulocyte-colony stimulating factors, platelet-derivedendothelial growth factor, PR39, PR11, angiogenin, a PHD inhibitor, andan eNOS enhancer.
 14. The method of claim 12, wherein the cell survivalpromoting factor is selected from the group consisting of aninsulin-like growth factor, a human growth factor, a HMG-CoA reductaseinhibitor and a capsase inhibitor.
 15. The method of claim 12, whereinthe endogenous recruiting factor is one of human growth factor orstromal cell-derived factor
 1. 16. A method of manufacturing acomposition comprising: combining at least one treatment agent with aprecursor of a sustained-release carrier in a solvent to form a mixture;processing the mixture to form a sustained-release carrier loaded with atreatment agent selected for treating a post-myocardial infarction areaof a heart; and adding the sustained-release carrier loaded with thetreatment agent to one of a first component solution or a secondcomponent solution of a two-component gel system to form a compositionthat is injected into a post-myocardial infarction area of a heartseparate from the other of the first component solution or the secondcomponent solution, wherein the first component solution comprises aself-assembled peptide selected from the group consisting of SEQ ID NO:1, SEQ ID NO: 2 and SEQ ID NO: 3 and the second component solutioncomprises an osmolarity modifying substance, and wherein thetwo-component gel system has a property, upon mixing of the firstcomponent solution with the second component solution in situ, ofserving as a gel scaffold to support a tissue within the post-myocardialinfarction area.